MINOR: ssl: Call callback function after loading SSL CRL data

MINOR: ssl: Call callback function after loading SSL CRL data

Due to the possibility of calling a control process after adding CRLs, the
ssl_commit_crlfile_cb variable was added.  It is actually a pointer to the
callback function, which is called if defined after initial loading of CRL
data from disk and after committing CRL data via CLI command
'commit ssl crl-file ..'.

If the callback function returns an error, then the CLI commit operation
is terminated.

Also, one case was added to the CLI context used by "commit cafile" and
"commit crlfile": CACRL_ST_CRLCB in which the callback function is called.

Signed-off-by: William Lallemand <wlallemand@haproxy.com>